Optical switch device employing a fluorescent substance with a radioactive element as a light source

ABSTRACT

This invention relates to an optical switch device including a light spot composed of a fluorescent substance in combination with radioactive elements or a pattern of a plurality of light spots and light detectors each manually moved relative to the light spots to detect a fluorescence from each fluorescent substance. An on-off pattern switching signal or a codified switching signal is obtained from an output from each light detector.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to an optical switch device whereinswitching pattern signals are obtained by allowing and disallowing alight from a light source to impinge on a light detector, and moreparticularly to the optical switch device wherein a fluorescentsubstance is employed as the light source.

2. Description of the Prior Art

Switch devices wherein a combination of a light-emitting diode and aphototransistor is utilized have been contemplated to replace the switchdevices having switch contacts. For example, in one of such switchdevices, a light guiding member formed of a plastic material or anoptical fiber provides a light passageway for a light between thelight-emitting diode and the phototransistor, and a shutter is movedinto and out of the light passageway.

According to the above-described switch device, the light-emitting diodeis required to be normally held "on." Thus, the prior art switch deviceemploying the light-emitting diode and the phototransistor has adisadvantage in electric power consumption.

SUMMARY OF THE INVENTION

Therefore, an object of this invention is to provide an optical switchdevice employing a fluorescent substance as the light source, whereinpower consumption is reduced and wherein the construction of the switchdevice is simplified.

The optical switch device in accordance with this invention comprises afluorescent substance constantly emitting a fluorescence in combinationwith a radioactive element, a light guiding member guiding thefluorescence from the fluorescent substance, an operating memberselectively allowing the fluorescence to impinge on the light guidingmember when displaced, and a light detector provided so as to detect thefluorescence guided by the light guiding member to thereby generate aswitching signal.

According to the above-described construction, when the operating memberis not displaced, the fluorescence from the fluorescent substance doesnot impinge on the light guiding member. Accordingly, no switchingsignal is generated by the light detector. When the operating member isdisplaced manually or with other means, the fluorescence from thefluorescent substance impinges on the light detector through the lightguiding member, whereby the switching signal is generated by the lightdetector.

The invention is applied to an optical switch device for unlockingautomobile doors, which comprises a key inserted into a keyhold forunlocking a door and a light detector detecting light from light spotswhich constitute key signal codes optically provided by the key. Thefluorescent substance is employed as a light source of the light spots.Accordingly, no electric power is required to be supplied to the lightsource and electrical wiring for the light source is denecessitated.

Furthermore, the invention is applied to a wiper switch, comprising amovable responsive member in which location signal codes comprised oflight spots formed of the fluorescent substance, and a light detectorprovided so as to be opposed to a movement locus of the responsivemember so that the light from the light spots is detected when theresponsive member passes the light spots.

In the above-described construction, the power supply to the lightsource is also not required and the electrical wiring is denecessitated.

Other and further objects of this invention will become obvious upon anunderstanding of the illustrative embodiments about to be described orwill be indicated in the appended claims, and various advantages notreferred to herein will occur to one skilled in the art upon employmentof the invention in practice.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 is a longitudinal section of the optical switch device of a firstembodiment in accordance with this invention;

FIG. 2 is an expanded perspective view of the optical switch device inFIG. 1;

FIG. 3 is a view similar to FIG. 1 showing the optical switch devicewherein the operating member is depressed;

FIG. 4 is a view similar to FIG. 1 showing the switch device of a secondembodiment;

FIG. 5 is an exploded perspective view of the switch device for keyunlocking of a third embodiment;

FIG. 6 is a circuit diagram employed in the device in FIG. 5;

FIG. 7 is a block diagram showing a signal processing circuit employedin the device in FIG. 5;

FIG. 8 shows code patterns of key signals;

FIG. 9 is a view similar to FIG. 5 showing the switch device of a fourthembodiment;

FIG. 10 is a sectional view of the wiper switch device of a fifthembodiment;

FIG. 11 is a sectional view taken along line XI--XI in FIG. 10;

FIG. 12 is a circuit diagram for the light detector employed in thedevice in FIG. 10; and

FIG. 13 shows code patterns of location signals employed in the devicein FIG. 10.

DESCRIPTION OF PREFERRED EMBODIMENTS

First Embodiment (See FIGS. 1-3):

There is shown in FIGS. 1, 2 and 3 the optical switch device of a firstembodiment. Referring first to FIGS. 1 and 2, numeral 1 indicates alight guiding member formed of a transparent plastic plate and having arectangular flat configuration. The light guiding member 1 has a centralrectangular opening 1a. As shown in FIGS. 1 and 2, a right-hand edgeportion of the light guiding member 1 is cut at an angle of 45° to topand under surfaces thereof so as to serve as a reflecting surface 1b. Alight shielding plate 2 is provided on the light guiding member 1. Thelight shielding plate 2 is formed of a plastic material having a lightshielding effect and has the same rectangular configuration as the lightguiding member 1. The light shielding plate 2 is provided with a centralopening 2a having the same configuration as the opening 1a. A spacer 3provided on the light shielding plate 2 is formed of a plastic materialhaving a light shielding effect and has a rectangular frame-likeconfiguration and the same outer configuration as the light shieldingplate 2. Accordingly, a central space 4 communicates with the openings1a and 2a. An operating plate 5 provided on the spacer 3 is formed of aplastic film with elasticity. The operating plate 5 has the same outerconfiguration as the spacer 13.

Numeral 6 indicates a fluorescent substance of a rectangular flatconfiguration. The fluorescent substance 6 is combined with aradioactive element so as to constantly emit a fluorescence. Thefluorescent substance 6 is mounted on a central under surface of theoperating plate 5 with a support plate 7 inserted therebetween so thatthe fluorescent substance 6 is normally positioned within the opening2a. In this position, an under surface of the fluorescent substance 6 isplaced at least above a top suface of the light guiding member 1.Accordingly, the fluorescence emitted from the fluorescent substance 6does not constantly impinge on the light guiding member 1. A black paintis coated on or a light shielding film is applied to the under surfaceof the fluorescent substance 6 by means of adhesive or the like tothereby provide a light shielding layer 8. When a top surface of theoperating plate 5 is depressed with a finger or the like, the operatingplate 5 suffers from elastic deformation as shown in FIG. 3. As theresult of elastic deformation of the operating plate 5, the fluorescentsubstance 6 is displaced into the opening 1 a and opposed to an innerperipheral surface of the light guiding member 1, thereby allowing thefluorescence to impinge on the light guiding member 1. When the fingeris released, the operating plate 5 returns to the normal state shown inFIG. 1. An under surface of the light guiding member 1 except partopposed to the reflecting surface 1b is covered with a rectangularopaque reinforcement 9.

A phototransistor 10 as a light detector is placed below the reflectingsurface 1b in opposed relation thereto. When the fluorescence from thefluorescent substance 6 impinges on the light guiding member 1, thefluorescence is reflected on the reflecting surface 1b to be detected bythe phototransistor 10. When the fluorescence is detected by thephototransistor 10, it generates switching signals.

The light guiding member 1, light shielding plate 2, the spacer 3, theoperating plate 5 and the reinforcement 9 are fixed by means of adhesiveor for holding peripheral edges thereof.

According to the above-described arrangement, in normal condition, thatis, when the operating plate 5 does not suffer from elastic deformation,the fluorescent substance 6 is no opposed to the inner peripheralsurface 1c of the light guiding member 1. Consequently, since thefluorescence from the fluorescent substance 6 does not impinge on thephototransistor 10, the switching signals are not generated. When thecentral top surface of the operating plate 5 is depressed, thefluorescent substance 6 is displaced to be opposed to the innerperipheral surface 1c of the light guiding member 1 as shown in FIG. 3.As shown by arrow in FIG. 3, the fluorescence from the fluorescentsubstance 6 is guided through the light guiding member 1 and reflectedon the reflecting surface 1b is be detected by the phototransistor 10.Thus, while the central top surface of the operating plate 5 is beingdepressed, the switching signals are generated by the phototransistor10. When the operating plate 5 is returned to the normal state shown inFIG. 1, the switching signals are not generated.

In the optical switch device of the first embodiment, the fluorescentsubstance 6 combined with the radioactive element is employed as thelight source. Electric consumption is reduced when the switch device ofthis embodiment is compared with the prior art optical switch deviceswherein the light-emitting diode is employed as the light source.Furthermore, a light passageway is provided only by the light guidingmember 1 and each of the light guiding member 1, the light shieldingplate 2, the spacer 3, the operating plate 5 and the reinforcement 9 isformed into a simple configuration and produced at low cost. Thesemembers are stacked one upon another, so that the optical switch deviceof the embodiment has a simple construction and the production costthereof is decreased. Additionally, since the movable portion of theswitch device also has a simple arrangement, the switch device isrendered small-sized and thinner as compared with the prior art opticalswitch devices. The abovementioned parts are produced by means of press,so that the productivity of the switch device is highly improved.Furthermore, the invention can be applied to a multiswitch device bychanging the configuration of the light guiding member 1 and the lightshielding plate 2. The switch device of this invention thus has anadvantage in wider fields of application.

Although the light guiding member 1 has the reflecting surface 1b, itmay be eliminated. For example, the reflecting surface 1b isdenecessitated where the phototransistor 10 is placed as shown byalternate long and two short dashes line in FIG. 1. Furthermore, thelight guiding member 1 may be a hollow member.

Second Embodiment (See FIG. 4):

In a second embodiment, identical parts are labelled by the samereference numerals as those in the first embodiment. Referring to FIG.4, a space defined by two light shielding plates 11 and 12 serves as alight passageway 13. The phototransistor 10 is provided in the vicinityof an outer end portion of the light passageway 13 so that thefluorescence from the fluorescent substance 6 is guided through thelight passageway 13 and that the fluorescence guided by the lightpassageway 13 is detected by the phototransistor 10. The fluorescentsubstance 6 is provided at the inner end of the light passageways 13. Amovable member 14 provided on the under surface of the operating plate 5extends through slits 11a and 12a formed in the light shielding plates11 and 12 respectively. The movable member 14 includes a shutter portion14a and an opening 14b. When the operating plate 5 is not depressed, theshutter portion 14a of the movable member 14 is positioned within thelight passageway 13 and the opening 14b is positioned outside the lightpassageway 13.

In operation of the device of the second embodiment, when the operatingplate 5 is not depressed as shown in FIG. 4, the fluorescence from thefluorescent substance 6 is blocked by the shutter portion 14a of themovable member 14. Accordingly, the fluorescence from the fluorescentsubstance 6 is not detected by the phototransistor 10. When theoperating plate 5 is depressed, the movable member 14 is moved in thedirection of arrow 15 in FIG. 4. With the movement of the movable member14, the shutter portion 14a is moved outside the light passageway 13 andthe opening 14b is moved into the light passageway 13. The fluorescencefrom the fluorescent substance 6 passes through the opening 14b to bedetected by the phototransistor 10. Thus, the switching signals aregenerated.

Third Embodiment (See FIGS. 5-8):

FIGS. 5-8 show a third embodiment wherein the invention is applied to adoor unlocking switch device for automobiles. Referring to FIG. 5,numeral 21 indicates a key, which is inserted into and pulled out of akeyhold (not shown) formed in a rotor A. Two lines 22 and 23 of sevenslits are formed in the lengthwise direction of the the key 21 so thatkey signal codifying light spots are provided. Each of the lines 22 and23 is comprised of, for example, seven slits. Each slit serves as acodified signal generating point. In the lines, predetermined slits areemployed as photo-signal generating slits 22a-22d and 23a-23drespectively. For example, in this embodiment, second, fourth, sixth andseventh slits in the line 23 are employed as the photo-signal generatingslits. A fluoresecent substances 24, each of which constantly emits afluorescence in combination with a radioactive element, is embeddedwithin the photo-signal generating slits 22a22d and 23a-23d.Accordingly, the fluorescence is constantly emitted through each of theslits 22a-22d and 23a-23d. Many kinds of keys are made by changing thelocation and number of photo-signal generating slits. One of the firstrow of slits is used as the photo-signal generating slit to discriminatebetween obverse and back of the key 21.

A light detector 25 is provided at one side of the rotor A. The lightdetector 25 comprises fourteen optical fibers 25a and fourteenphototransistors 25b. When the key 21 is inserted into the keyhold,distal end surfaces of the optical fibers 25a are opposed to the lines22 and 23 of slits respectively. The phototransistors 25b are providedin opposite relation to rear end surfaces of the optical fibers 25brespectively.

As shown in FIG. 6, a collector of each phototransistor is connected toa power-supply terminal +Vcc and an emitter thereof is grounded througha resistance 26. When each phototransistor 25a detects the fluorescencefrom corresponding fluorescent substance 24, a logic level "1" signal issupplied from corresponding output terminals 27. That is, when the key21 is inserted into the keyhold, the fluorescence from each fluorescentsubstance 24 impinges, through each of the photo-signal generating slits22a-22d and 23a-23d, on corresponding phototransistor 25b, whichgenerates a codified signal Sc composed of logic signal in accordancewith a codified arrangement set on the key 21. More concretely, wherethe photo-signal generating slits 22a-22d and 23a-23d are set as shownin FIG. 5, each phototransistor 25a corresponding to each of the firstto seven slits of the lines 22 and 23 generates a codified signal Sc. Inthis case, a combination of the codified signals Sc is shown in FIG. 8.

FIG. 7 schematically shows a manner of processing the codified signalsSc. Numeral 28 indicates a means for decoding the codified signals Sc.The codified signals Sc are supplied to the decoding means 28 from thephototransistors 25a. A door unlock signal So is generated from thedecoding means 28 when the codified signals Sc coincide with presetcodified signals. Based on the first row of the codified signals SCsupplied, which correspond to the codes of the first row in FIG. 8, thedecoding means 28 discriminates between obverse and back of the key 21.The result of discrimination is utilized for the decoding of thecodified signals Sc in the decoding means 28.

Numeral 29 indicates a drive circuit which is supplied with the doorunlocking signal from the decoding means 28. When supplied with the doorunlocking signal So, the drive circuit 29 operates to drive anelectromagnetic solenoid 30 as a door unlocking means. Drive of theelectromagnetic solenoid 30 causes the rotor A to rotate, whereby thekey is turned.

According to the third embodiment, since the fluorescent substances 24are employed as light source for generating the codified signals,consumption of electric power is reduced as compared with the prior artoptical switch device wherein the light source is required to be alwayssupplied with electric power. Accordingly, when the switch device of thethird embodiment is mounted in the automobile, a battery is preventedfrom being overdischarged. Furthermore, since relatively expensive lightsource and electrical wiring for the light source are denecessitated,the production cost of the switch device is decreased and the assemblywork of the switch device is simplified. Furthermore, the light sourceis not provided at the side of the rotor A. The light source for thephototransistor is first provided when the key 21 is inserted into thekeyhold.

Although the photo-signals from the key 21 are processed in a staticmanner by disposing the fourteen phototransistors 25b in accordance withthe fourteen slits of the lines 22 and 23, the photo-signals may beprocessed in a dynamic manner. In this case, based on the output fromeach of two phototransistors for the lines 22 and 23 of the slits, thephoto-signals from the key 21 are processed. The output from thephototransistor varies in time series when the key is inserted into thekeyhold.

Fourth Embodiment (See FIG. 9):

FIG. 9 shows the switch device of a fourth embodiment, in which the sameeffect can be obtained as in the third embodiment. Numeral 31 indicatesa key on which photosignal generating slits 32a-32d and 33a-33d providedin accordance with a predetermined codified arrangement are formed inthe lengthwise direction thereof. A fluorescent substance 34 having arectangular flat configuration is provided so that when the key 31 isinserted into the keyhold, the fluorescent substance 34 is opposed tothe light detector with the key positioned therebetween. When the key 31is inserted into the keyhold, the fluorescence from the fluorescentsubstance 34 is detected through the slits 32a-32dand 33a-33d by thelight detector 25.

Fifth Embodiment (See FIGS. 10-13):

In a fifth embodiment, the invention is applied to a wiper switch forautomobiles. Referring to FIGS. 10 and 11, a plastic case 41 has asectorial underside wall 41a and a side wall 41b extending upwardly fromthe peripheral edge of the underside wall 41a. An opening 41c is formedat a pivot portion of the sector as shown in FIG. 11. A support opening41d is formed at a portion of the underside wall 41a, which portion isin the vicinity of the opening 41c. Numeral 42 indicates a sectorialplastic cover which covers an upper opening of the case 41. A supportslit 42a is formed at a portion of the cover 42 opposed to the supportslit 41d. A plastic bracket 43 as responsive member has a sectorialconfiguration and a smaller area than the underside wall 41a. Thebracket 43 is rotatably mounted on axes 43a and 43b formed on the pivotportion thereof and inserted into the support slits 41d and 42a. Numeral44 indicates an operating lever as operating member, which is formedintegrally with the bracket 41. The operating lever 44 projects throughthe opening 41c outside the case 43. The bracket 43 is moved with theoperating lever 44. In the embodiment, when the operating lever 44 isoperated, the bracket 43 is selectively moved from an off-position OFFto an intermittent wipe mode position INT, a low speed wipe modeposition LO and a high speed wipe mode position HI. A detent mechanism45 holds the bracket 43 at each wipe mode position. The detent mechanism45 is composed of a portion 45a formed on an arc portion thereof, adetent ball 45b provided with in a recess 43c formed in the bracket 43,and a compression spring 45c for depressing the detent ball 45b againstthe portion 45a.

Phototransistors 46 and 47 as light detectors are provided with opticalfibers 46a and 47a respectively. The distal edge surface of each opticalfiber serves as a light detecting surface. The distal edge of eachoptical fiber inserted through the underside wall 41a of the case 41 sothat the distal edge surface of each optical fiber is opposed to amovement locus of the bracket 43. Three pairs of fluorescent substancelocating portions 48a and 48b, 49a and 49b, 50a and 50b are provided onthe under surface of the bracket 43. When the bracket 43 is positionedat each of the mode positions INT, LO and HI, the fluorescent substancelocating portions are opposed to the distal edge surfaces of the opticalfibers 46a and 47a. The fluorescent substance locating portions areshown by broken lines in FIG. 11. In the embodiment, the fluorescentsubstances 51-54 each constantly emitting a fluorescence in combinationwith a radioactive element are disposed on the fluorescent substancelocating portions 48a and 48b, 49a and 49b, 50a and 50b in the followingmanner. When the bracket 43 is moved to the high speed wipe modeposition HI, the fluorescent substances 51 and 52 are disposed on thefluorescent substance locating portions 48a and 48b respectively whichare opposed to the distal edge surfaces of the optical fibers 46a and47a. When the bracket 43 is moved to the low speed wipe mode positionLO, the fluorescent substance 53 is disposed on the fluorescentsubstance locating portion 49a which is opposed to the distal edgesurfaces of the optical fibers 46a and 47a together with the fluorescentsubstance locating prtion 49b. When the bracket 43 is moved to theintermittent wipe mode position INT, the fluorescent substance 54 isdisposed on the fluorescent substance locating portion 50b which isopposed to the distal edge surfaces of the optical fibers 46a and 47atogether with the fluorescent substance locating portion 50a.

FIG. 12 shows a circuit arrangement for obtaining a switching output inaccordance with the photo reception of the phototransistors 46 and 47. Acollector of each phototransistor is connected to a power-supplyterminal +Vcc and an emitter of each phototransistor is grounded througheach of resistances 55 and 56. Output signals are supplied from outputterminals 57 and 58 connected to the emitters of the phototransistors 46and 47 respectively in the following manner. When the bracket 43 ispositioned at the off-position OFF, the fluorescent substance are notopposed to the distal edge surfaces of the optical fibers 46a and 47a.Accordingly, since the phototransistors 46 and 47 are turned off, logiclevel "0" signals are supplied from the output terminals 57 and 58respectively. When the bracket is moved from the off-position OFF to theintermittent wipe mode position INT, the fluorescent substance 54 areopposed to the distal edge surface of the optical fiber 46a. Thephototransistor 46 detects the fluorescence from the fluorescentsubstance 54 to be thereby turned on. The logic level "1" signal issupplied from the output teminal 57 in accordance with a voltage levelat the power-supply terminal +Vcc and the logic level "0" signal issupplied from the output terminal 58. When the bracket 43 is moved tothe low wipe mode position LO, the fluorescent substance 53 is opposedto the distal edge surface of the optical fiber 47a. Since thephototransistor 47 is turned on, the logic level "1" signal is suppliedfrom the output terminal 58 and the logic level "0" signal is suppliedfrom the output terminal 57. When the bracket 43 is moved to the highspeed wipe mode position HI, the fluorescent substances 51 and 52 areopposed to the distal edge surfaces of the optical fibers 46a and 47a.Accordingly, since the phototransistors 46 and 47 are turned on, thelogic level "1" signals are supplied from the output terminals 57 and 58respectively. That is, codified switching signals are supplied from theoutput terminals 57 and 58 in accordance with the location of thebracket 43 as shown in FIG. 13, thereby controlling operation of wipers.

In the above-described wiper switch device, since switch contacts arenot employed, the life of the device is not shortened owing to wear ofthe contacts. Although three mode positions INT, LO and HI are providedother than the off-position, only two phototransistors are employed,thereby the number of wires for signal output is decreased. Furthermore,since each of the fluorescent substances 51-54 has a small thickness,the switch device is rendered small-sized and thinner. Additionally,since the fluorescent substances each normally emitting a fluorescenceare employed as the light sources, electric power consumption is reducedwhen the switch device of this embodiment is compared with the prior artwiper switch devices wherein the light-emitting diode is employed as thelight source. Although the phototransistor 46 and 47 are provided withthe optical fibers 46a and 47a respectively in the above-describedembodiment, the optical fibers may be eliminated.

The foregoing disclosure and drawings are merely illustrative of theprinciples of this invention and are not to be interpreted in a limitingsense. The only limitation is to be determined from the scope of theappended claims.

What is claimed is:
 1. An optical switch device comprising:(a) afluorescent substance constantly emitting a fluorescence in combinationwith a radioactive element; (b) a light detector detecting thefluorescence emitted from said fluorescent substance, said lightdetector generating a switching signal when detecting the fluorescenceemitted from said fluorescent substance; and (c) a displaceableoperating member provided to move the fluorescent substance relative tothe light detector so that the fluorescence emitted from saidfluorescent substance is allowed to impinge on said light detector whensaid operating member is displaced.
 2. An optical switch device asdefined by claim 1, which further comprises means for guiding thefluorescence emitted from said fluorescent substance therethrough sothat the fluorescence emitted from said fluorescent substance isdirected to impinge on said light detector when said operating member isdisplaced.
 3. A door-unlocking optical switch device comprising:(a) akey adaptable to be inserted into a keyhold and to be extractedtherefrom; (b) a plurality of slit lines formed in said key inaccordance with a predetermined codified arrangement; (c) fluorescentsubstances constantly emitting a fluorescence in combination withradioactive elements respectively, the fluorescence passing through saidslits; and (d) light detectors positioned to detect the fluorescencethrough said slits when said key is inserted into the keyhold, each saidlight detector generating a codified signal when detecting thefluorescence from said respective fluorescent substances.
 4. Adoor-unlocking optical switch device for automobiles comprising:(a) akey inserted into a keyhold and extracted therefrom; (b) a plurality ofslit lines formed in said key in accordance with a predeterminedcodified arrangement; (c) fluorescent substances constantly emitting afluorescence in combination with radioactive elements respectively, thefluorescence passing through said slits; and (d) light detectorsdetecting the fluorescence through said slits when said key is insertedinto the keyhold, each said light detector generating a codified signalwhen detecting the fluorescence from said respective fluorescentsubstances.
 5. An optical switch device comprising:(a) a responsivemember movable between a plurality of operative positions; (b) aplurality of fluorescent substances adjacent to the responsive member,each substance constantly emitting a fluorescence in combination withradioactive elements respectively; (c) a plurality of light detectorspositioned to detect the fluorescence emitted from said respectivefluorescent substances, said light detectors being provided so as to beopposed to a movement locus of said responsive member; and (d) aplurality of fluorescent substance locating portions formed on saidresponsive member so as to be opposed to said light detectorsrespectively when said responsive member is moved to the respectiveoperative positions, said fluorescent substances being selectivelydisposed on said fluorescent substance locating portions.